Lambda: IntUnaryOperator applyAsInt avoids boxing in a numeric transform

IntUnaryOperator takes and returns a primitive int, making it the boxing-free counterpart of UnaryOperator<Integer> for simple numeric transforms.

Code

IntUnaryOperator square = n -> n * n;
System.out.println("square.applyAsInt(6) = " + square.applyAsInt(6));
System.out.println("square.applyAsInt(-3) = " + square.applyAsInt(-3));

Output

square.applyAsInt(6) = 36
square.applyAsInt(-3) = 9